科讯sql商业版中用到的ajax空间与分页函数,他们的js代码学习是非常不错的
//ajax 控件
function PageAjax(){
    var xhrObj=null;
    if(window.XMLHttpRequest)
    {
    xhrObj=new XMLHttpRequest();
    }
    else if(window.ActiveXObject)
    {
    try{
    xhrObj=new ActiveXObject("Microsoft.XMLHTTP");
    }
    catch(e1)
    {
    try{
    xhrObj=new ActiveXObject("MSXML2.XMLHTTP");
    }
    catch(e2){
    try{
    xhrObj=new ActiveXObject("MSXML3.XMLHTTP");
    }
    catch(e3){
    alert("创建Ajax失败："+e3)
    }
    }
    }
    }
    else
    {
    alert("未能识别的浏览器");
    }
    return xhrObj;
}

function Page(curPage,labelid,classid,installdir,url,refreshtype,specialid)
   {
   this.labelid=labelid;
   this.classid=classid;
   this.url=url;
   if (labelid.substring(0,5)=="{SQL_")
   {
    var slabelid=labelid.split('(')[0];
    slabelid=slabelid.replace("{","");
    this.c_obj="c_"+slabelid;
    this.p_obj="p_"+slabelid;
   }
   else
   {
   this.c_obj="c_"+labelid;
   this.p_obj="p_"+labelid;
   }
   this.installdir=installdir;
   this.refreshtype=refreshtype;
   this.specialid=specialid;
   this.page=curPage;
   loadData(1);
   }
function loadData(p)
{  this.page=p;
   var xhr=new PageAjax();
   xhr.open("get",installdir+url+"?labelid="+escape(labelid)+"&classid="+classid+"&refreshtype="+refreshtype+"&specialid=" +specialid+"&curpage="+p,true);
   xhr.onreadystatechange=function (){
             if(xhr.readyState==1)
              {
                 if (p==1)
                eval('document.all.'+c_obj).innerHTML="<div align='center'><img src='"+installdir+"images/loading.gif'>正在连接服务器...</div>";
              }
              else if(xhr.readyState==2 || xhr.readyState==3)
              {
                if (p==1)
                eval('document.all.'+c_obj).innerHTML="<div align='center'><img src='"+installdir+"images/loading.gif'>正在读取数据...</div>";
              }
              else if(xhr.readyState==4)
              {
             if (xhr.status==200)
             {
                  var pagearr=xhr.responseText.split("{ks:page}")
                  var pageparamarr=pagearr[1].split("|");
                  count=pageparamarr[0];    
                  perpagenum=pageparamarr[1];
                  pagecount=pageparamarr[2];
                  itemunit=pageparamarr[3];   
                  itemname=pageparamarr[4];
                  pagestyle=pageparamarr[5];
                  getObject(c_obj).innerHTML=pagearr[0];
                  pagelist();
             }
            }
       }
    xhr.send(null); 
}
function getObject(id) 
{
    if(document.getElementById) 
    {
        return document.getElementById(id);
    }
    else if(document.all)
    {
        return document.all[id];
    }
    else if(document.layers)
    {
        return document.layers[id];
    }
}

function pagelist()
{
 var n=1;    
 var statushtml=null;
 switch(parseInt(this.pagestyle))
 {
  case 1:    
     statushtml="共"+this.count+this.itemunit+" <a href=\"javascript:homePage(1);\" title=\"首页\">首页</a> <a href=\"javascript:previousPage()\" title=\"上一页\">上一页</a>&nbsp;<a href=\"javascript:nextPage()\" title=\"下一页\">下一页</a> <a href=\"javascript:lastPage();\" title=\"最后一页\">尾页</a> 页次:<font color=red>"+this.page+"</font>/"+this.pagecount+"页 "+this.perpagenum+this.itemunit+this.itemname+"/页";
        break;
  case 2:
     statushtml="<a href='#'>"+this.pagecount+"页/"+this.count+this.itemunit+"</a> <a href=\"javascript:homePage(1);\" title=\"首页\"><font face=webdings>9</font></a> <a href=\"javascript:previousPage()\" title=\"上一页\"><font face=webdings>7</font></a>&nbsp;";
     var startpage=1;
     if (this.page==10)
       startpage=2;
     else if(this.page>10)
       startpage=eval((parseInt(this.page/10)-1)*10+parseInt((this.page)%10)+2);
      for(var i=startpage;i<=this.pagecount;i++){ 
          if (i==this.page)
           statushtml+="<a href=\"#\"><font color=\"#ff0000\">"+i+"</font></a>&nbsp;"
          else
            statushtml+="<a href=\"javascript:turn("+i+")\">"+i+"</a>&nbsp;"
            n=n+1;
          if (n>10) break;
      }
     statushtml+="<a href=\"javascript:nextPage()\" title=\"下一页\"><font face=webdings>8</font></a> <a href=\"javascript:lastPage();\" title=\"最后一页\"><font face=webdings>:</font></a>";
     statushtml="<span class='kspage'>"+statushtml+"</span>";
    break;     
  case 4:
     statushtml="共"+this.pagecount+"页/"+this.count+this.itemunit+this.itemname+" <a href=\"javascript:homePage(1);\" title=\"首页\"><font face=webdings>9</font></a> <a href=\"javascript:previousPage()\" title=\"上一页\"><font face=webdings>7</font></a>&nbsp;";
      for(var i=this.page;i<=this.pagecount;i++){ 
          if (i==this.page)
           statushtml+="<b><font color=\"#ff0000\">"+i+"</font></b>&nbsp;"
          else
            statushtml+="<a href=\"javascript:turn("+i+")\">["+i+"]</a>&nbsp;"
            n=n+1;
          if (n>10) break;
      }
     statushtml+="<a href=\"javascript:nextPage()\" title=\"下一页\"><font face=webdings>8</font></a> <a href=\"javascript:lastPage();\" title=\"最后一页\"><font face=webdings>:</font></a>";
    break;     
  case 3:
     statushtml="第<font color=#ff000>"+this.page+"</font>页 共"+this.pagecount+"页 <a href=\"javascript:homePage(1);\" title=\"首页\"><<</a> <a href=\"javascript:previousPage()\" title=\"上一页\"><</a>&nbsp;<a href=\"javascript:nextPage()\" title=\"下一页\"</a> <a href=\"javascript:lastPage();\" title=\"最后一页\"></a> "+this.perpagenum+this.itemunit+this.itemname+"/页";
   break;
 }
     statushtml+="&nbsp;第<select name=\"goto\" onchange=\"turn(parseInt(this.value));\">";
      for(var i=1;i<=this.pagecount;i++){
         if (i==this.page)
         statushtml+="<option value='"+i+"' selected>"+i+"</option>";
         else
         statushtml+="<option value='"+i+"'>"+i+"</option>";
      }    
     statushtml+="</select>页";
     getObject(this.p_obj).innerHTML=statushtml;
}
function homePage()
{
   if(this.page==1)
    alert("已经是首页了！")
   else
   loadData(1);
} 
function lastPage()
{
   if(this.page==this.pagecount)
    alert("已经是最后一页了！")
   else
   loadData(this.pagecount);
} 
function previousPage()
{
   if (this.page>1)
      loadData(this.page-1);
   else
      alert("已经是第一页了");      
}

function nextPage()
{
   if(this.page<this.pagecount)
      loadData(this.page+1);
   else
      alert("已经到最后一页了");
}
function turn(i)
{
     loadData(i);
}